PHYSICS 12
Prof: Kim Griest
Formula sheet
Energy = Work = Force × Distance, (E = F d).
Potential Energy: P.E. = mgh.
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For gravity, g = 9.8m/sec , (F = weight = mg).
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Kinetic Energy: K.E. = 2 mv 2
Power = Energy/Time, (P = E/t, or E = P t), and also P = F v.
Heat energy: ∆E = cP m∆T .
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Wind Power: P/A2 = 6.1 × 10−4 v 3 (kW/m ), v in units of m/sec, Area, A, in m2 ; theoretical maximum efficiency is 59%.
Carnot Efficiency = (Thot − Tcold )/Thot ; T in 0 K.
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C = 95 (0 F − 32), 0 K =0 C + 273.
Coefficient of Performance (COP) = Thot /(Thot − Tcold ) = Qhot /(Qhot − Qcold ); T in 0 K.
Energy Efficiency Ratio (EER) = Tcold /(Thot − Tcold ) = Qcold /(Qhot − Qcold ) = Qcold /W ; T in 0 K.
Drag force Fad = CD Af v 2 /370; v in miles/hr, Af in ft2 , Fad in pounds.
Rolling force Fr = Cr mv, v in miles/hr.
Acceleraton force Facc = ma.
Hill climbing force Fh = msg.
Exponential growth N = N0 (1 + r)n
Energy loss: Q(Btu) = 24A(degree days)/RT ,
Q
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t (Btu/hr) = A(Ti − To )/R; T in F, A in ft .
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Degree-days = (65 F − Tout )(number of days)
Adiabatic Lapse Rate (ALR) = 3 0 F per 1000 ft
Price of fuels
42 Gallon barrel of oil: $130.00
1000 cubic feet of natural gas: $13.00
1 kilowatt hour of electricity: $0.12
1 gallon gasoline: $4.00
1 gram of Uranium: $0.10
Heat capacities in Btu/( ft3 0 F)
Water: 62
Wood: 29
Stone: 20
Concrete: 22
Facts and Factors
1 gallon of water weighs 8.3 pounds.
density of water is 1gm/cm3 .
1 Watt = 1 Joule/sec = 3.41 Btu/hr = 1.34 × 10−3 horsepower = 0.737 ft lb/sec.
1 Calorie = 1 kilocalorie = 1000 calories.
1 mile = 1609 meters = 5280 ft.
1ton = 2000lb = 0.907 metric tonne.
mass of proton and neutron about 1.67 ×10−27 kg.
Methane is CH4 , Carbon Dioxide is CO2
speed of light = 3 × 108 meters/sec
1 ft = 0.3048 meter
1 kg = 2.2 lbs
2006 population of the U.S. is about 300 million
R-values: inside air layer:0.68, outside air layer:0.17, glass:0.03, plywood:0.94
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